Liberal Democrat leadership candidate Chris Huhne played the 'age card' last night, saying that his experience would stand him in good stead against his younger rival, Nick Clegg.

As the two candidates for the Liberal Democrat leadership went head-to-head for the first time, Huhne said he had fought three general elections and had the political ballast to lead the party.

Although 66-year-old Sir Menzies Campbell said last week that he was forced to resign as leader because of the media's constant sniping about his age, the issue has risen again, partly because it is one of the few differences between 53-year-old Huhne and his rival, Nick Clegg, 40, both seen as modernisers within the party.

Clegg is currently the bookies' favourite to win the contest, which will be decided on the votes of 55,000 Lib Dem activists before Christmas. But in an interview with The Observer, Huhne, the party's environment spokesman, said that he had more experience, having also been an MEP for six years.

Huhne, who stood against Campbell in the last leadership contest, said: 'The fact that I fought and lost two elections in the Eighties before going into the European Parliament does give you a breadth of experience. I have enormous sympathy for people who are battling away at the grass roots, trying to achieve change.'

Like Clegg, he came from a privileged background, having been to Westminster School and Oxford. 'But I do believe passionately that society must not waste the talent of anyone, and we have to improve the chances for those coming from all parts of society, particularly through the education system. One of the things that matters most to me is social justice, the sense that, wherever you come from, you have the opportunity to go anywhere. If you fall on hard times, if you are unemployed, if you are a pensioner and lose your private pension provision, then we have to ensure that the public safety net is generous, is able to pick you up and, in the case of the NHS, give you world-class care.'

Both candidates were making their first public pitches yesterday. In what has become a two-horse race, both are competing to show they have the support of Charles Kennedy, the former leader who stood down two years ago when his problems with drink became apparent but remains hugely popular within the party.

Huhne, the MP for Eastleigh in Hampshire, has appointed two key Kennedy supporters, Dick Newby and Anna Werrin, to work respectively as his campaign treasurer and manager. In a pointed snub to Clegg, Newby, who was Kennnedy's chief of staff, said: 'I'm convinced Chris Huhne is the right man to lead the party. The public are tired of Identikit politicians who put style over substance.'

Clegg, meanwhile, said that he would ask Kennedy to be part of a new committee to help guide his leadership. He has written to Kennedy and plans similar invitations to Campbell and senior Lib Dem figures Paddy Ashdown, David Steel and Shirley Williams to set up what is known within his camp as 'the committee of the greybeards'.

Over the past 18 months Kennedy had shown little enthusiasm for serving under Campbell, who his friends blamed for using his drink problem to overthrow him. With Campbell gone, Clegg hopes he can persuade Kennedy to play a full part. Kennedy himself was not saying which candidate he would back. An aide said: 'He feels it wouldn't be right to use his position as a former leader to do so.'

Huhne will campaign on a ticket of civil liberties, a key Liberal tradition. 'We cannot abandon our freedoms, such as the right to a jury trial, the right to freedom of expression and the freedom to demonstrate, and also against the abuse of the anti-terrorism laws,' he said.

Latest odds put Clegg in a commanding lead. At Ladbrokes the odds on him becoming leader improved from 1/3 to 2/7. Huhne was out to 5/2 from 9/4.